Hi Morten,
very interesting post! I played a lot with fin sizes on the iSonic 122 2009 and went up to 48cm, which gave me solid speed and control. My weight is in between 83 and 85 kg. But after testing with teammates, especially with Jesper Orth, I realised, that my gear was trimmed too extreme. Boom too high and masttrack too far back. Now I came back to an average trimm: enough downhaul, mastbase around the sweet spot (recommended position), 44 fin, front straps middle, backstraps middle or back and boom much lower by 5-8 cm.
The result: more comfort, better locked sail, more control in the jibe and no spinouts, because my bodyweight sits deeper.
Try this out and you will perhaps decide to get a 46 or 44 inside the board. If you will be powered up on the 48, you can realize that the board starts to work a lot along its midleline and doesn´t fly so stable over the water, how it should. Just watch the nose of the board when you feel that the whole system gets powered up. With a shorter fin you will have much more stability. But it depends, what you are looking for: a gearset, which works great on the upwind or a set, which should be a winner on the downwind. And the watersurface has a big influence on your trimm. I would suggest to have at least 2 finsizes for the 122. So you can pimp the board in lighter wind with the 48 and get the best tuning in stronger conditions with a 42 or 44. Depends on the model.

Have fun,
Chris

27th August 2009 04:36 PM

morten.g

Tanks for all responses. I bought a Drake r13 sl 48. I have tried it a couple of times and it works perfect for me. Mutch more speed, no spin-out and that gives me easier jibes.

Morten

24th August 2009 06:54 AM

Remi

Hi Morten,

Please try this : remove the fin sticker by sanding with minimum 600 gr and all the fin from base to head, it should be stop your spin out.

All the best

22nd August 2009 05:32 AM

k871mark

I alternate between Drake 40 & 42cm fins with 8m GTX depending on sea state
but I'm quite happy with Drake 46cm fin for 9m Vapor whatever the conditions.
I'm 72kgs and prefer to use a seat harness to keep the weight off my feet.

14th August 2009 10:22 PM

Per

Hi Morten.
First of all you have to be sure that it's a fin and not a sail problem that makes you spin out. I (95 kgs) have an iS 122 and I don't have any problems with my Drake 46 with a 8.5 sail - except that it actually feels a little too big - and I can use the Drake 40 comfortably (and faster) with the 8.5 when the wind is higher and steady.
How is your sail trimmed? Do you use enough downhaul (lots of surfere don't), and do ylu have an adjustable outhaul? What about foot strap position? Are you in balance on the board?

;-)
Per

14th August 2009 07:35 PM

Vando

Agree with Papounet you have so much control with the Venoms.
I use the 46 with my IS122 and Loft Blade 8.5 and wow the boards really does trim nicely.
The Venoms dont seem to try and overpower you like some other fins, I use this combo up to 25 knots im 85kg.

ta Vando

13th August 2009 10:20 PM

Papounet

Canefire is a fine fin, but iSonic 122 dont need as powerfull & stiff ones
Very fine at all for Fanatic Falcon 07/08.........

I was very pleased of the Tectonics Tomcat 42 with 8.4 on iSonic 125,
but the testing of the C3 Venom 40 with 7.4 throw me on an other world.
The board flyes flat over the water & feel free as never.
40 is Ok for flat water & well powered, otherwise 42 is a good choice with 7.4.

46/48 is nice for 8.4 see under

By Ian Fox

Quote:

Actually I was personally pretty doubtful that the G10 construction would be so good for hi load racing in sizes above 40cm, but for sure the Venom has proved that wrong. Normally once larger or powerful riders get onto larger G10 fins, the fin tends to deform too much under hi loads (especially possible with wider boards like iSonics where the rider has increased leverage over the fin compared to narrower or traditional slalom boards). This doesn't happen with the Venom, and in fact the Venom gets better as it gets faster and pushed harder. Taken to the limit, the most dominant feedback/sensation from the Venom is the insane control the fin can deliver at high speeds, which allows the rider unlimited confidence to just push on harder ~ and giving a "real world" speed advantage. Carrying speed and power into and around jibe marks is also a real advantage (in tight racing) with Venom.

Typically with slalom /race fins there is a size/point at which the rider starts to feel "overfinned" ~ and the advantage (especially with bigger/wider/modern/iSonic type slalom boards) of carrying "extra" fin tuning starts to work against the rider out on the water ~ with Venom, this point has been pushed back (so further UP the range). In real world conditions this allows the rider to use (and benefit) from a slightly larger (usually about +2cm) fin tuning for a given board/sail/conditions combo, without increasing the risk or problems from being overfinned too early.

[ Yes, it's true that extra fin size can be argued (in theory) as extra drag and slower, however that really is more a tuning concern for super fast speed trial equipment and conditions, and experienced users of boards like iSonic will know the advantage of carrying a little extra fin in most open water racing. Out on a slalom race course the wind (+conditions) will vary a lot throughout a race- and most often there is more to be gained by being fully powered (finned) as much of the time as possible, rather than having the lowest drag (and thus highest theoretical speed) - but never getting into that "top speed" range to benefit from it ! ]

The Venom feel thru the water is very typical "C3" fast/slippery (lo drag feel) - but in a lot of ways you also feel the fin twisting and "working". Compared to carbon the G10 may feel a bit "less crisp" but the Venom is certainly reactive, smoothly and calm underfoot. It's also very tolerant to angle of attack variance (rough riding...) which is often a problem with super fast foils used in rougher conditions. After a few runs your confidence builds (more than expected) and it's more like "forget about the fin" and just go for it ~ as hard as you can. This is very much the experience of many riders who have tried and found the Venom allowed them to take their performance to a higher level - and now adopted the Venoms as their choice for racing with iSonics.

Based on the better than expected performance of the G10 in Venom 46 and 48cm, a 50cm proto is in development right now.